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L. S. CH'ICHBSTEB..

APPARATUSTOR PULVBRIZING GRAIN, GRES, 650. NQ. 253,344.. l'Patented-Ps1). 7,1882

' ffy l N. PETERS. Pholw/Liuwgnpher, wnhngmn. n, C.

UNITED ASTATES PATENT OFFICE.

LEWIS S. CHICHESTER, OF JERSEY CITY, NEW JERSEY, ASSIGNOR, BY DIRECT ANDMESNE ASSIGNMENTS, TO CHARLES G. FRANCKLYN AND WILLIAM FOSTER, JE., oFNEW YORK, N. Y.

, APPARATUS lFOR PULVERIZING GRAIN, ORES, 80C.

SPECIFICATION forming part of Letters Patent No. 253,344, dated February7, 1882.

Application tiled April 19, 1880.

To all whom t may concern:

Be it known that I, LEWISl ScUDDER CHI- CHEsTER, of Jersey City, in thecounty ofHudson and State of New Jersey, United States ot America,vhaveinvented an Improvement in Apparatus for Dulverizing Grain, Ores,Minerals, and other Frangible Substances, of which the following is aspecification.

`Before my invention a blast of air had been ro used for giving motionto particles of sand for engraving glass, stone, and other substances,andin the grinding of grain a current of air had been employed to aidthe movement of the particles between two millstones, one of' 15 whichrevolved, andpercussion had been used for the pulverization of varioussubstances, the same resulting from the action of rapidlyrevolving armsor surfaces.

In Letters Patent No. 230,468, granted to zo me, an issuing jet of airis described as imparting a rapid movement to grain or other Inaterialto move it along between conveyingsurfaces and cause it to strike thevarious corrugations thereof for pulverizing such matez 5 rial. Achamber has also been provided, from which frangible substances havebeen ejected against a target and shattered, thel propelling force beinggunpowder, compressed air, or steam.

My invention relates to aniechanism for accomplishin g the same objectsby two or more successive impacts in the same apparatus, whereby therequired Iineness is obtained withont passing the material to bepulverized through the` apparatus so many times.

In carrying outmyimprovement I prefer to introduce the grain or otherfrangible material Athrough/a tube, around whichis a chamber forcompressed air, and an'annular nozzle for the 14o jet of air to draw thematerial through the central pipe and throw it with great violenceagainst a target that is placed opposite tothe issuing jet, and" aroundthis target is a case, that not onlyincloses the scatteringfragments,but it also presents a surface against which they are brought intoforcible contact by the rebound from the target, superinduced by there-enforcing action of the current of air as it passes around the ed gesof the target, so that at (No model.)

least two points of impact are presented to the material to bepulverized. A second chamber with compressed air and an annular nozzlewillusually be employed to direct the particles from the first reductionagainst a second target and the. interior of a second case, and thussecure the reduction ofthe grain or other frangible material to therequisite iiueness. In all instances the current of atmosphere actingaround the material to he pnlverized imparts the required speed toobtain the maximum effect by the impact upon the target, and

\ the rebound of the shattered particles from the target causes them toenter the current of at- Inosphere where it is traveling with the great#est velocity. Thereby the maximum velocity is reimparted, and theseparticles are thrown olf by centrifugal action against the inside ofthecase, as the air is compelled to pass around the edges of the target,thus insuring the most efficient action with the use of the small estquantity of atmosphere traveling at a speedv that would not be safe orpracticable with solid revolving devices.

In the drawings I have represented, in Figure 1, a section of theapparatus with two targets, and in Fig. 2 a face view of one of thetargets, with the case in section at the line ww.

The chamber a is to be supplied with air from any suitable pump orcompressor, and it is preferable to maintain a. pressure of four hundredor five hundred pounds to the square inch. The tube b conveys the air tothe branch pipes c c and chambers d d'; and at e is a hopper with apipe, f, through whichthe` from such target and passes around the edgesthereof, and the shattered material, rebounding through the current ofair, is propelled by the action of the air against the interiorof thecase l and strikes upon the same along the portion marked i i, and isagain shatteredand rebounds and is carried on through the tube m, andthe additional supply of air at the chamber d', issuing from the orificeg', gives a fresh impetus tothe frangible particles to break the sameagainst the second target, k', and case l. The convex shape of thetarget prevents the particles reboundingdirectlyagainst the movement ofthe impelling air and causes them and the air to diverge outwardly andpass more freely around the edges of the target within the case, asaforesaid, which case is sufficiently close for the material to strikeand be further shattered by the second impact. The bridge for the targetheilig behind such target, and having a central support to the back ofsuch target, the air is allowed to pass freely around the edges of thetarget at all sides, and there is not any support extending from thetarget tothe nozzle or pipe from which the materials are dischargedagainst such target. The support for thetarget being immediately behindthe point oi' impact renders the target more rigid and effective than itwould be it' supported at its edges, and the cross-bar for the centralsupport is Ilot liable to be injured and worn by the material that ispulverized, as it is at a distance from the points ofimpact. More thantwo of these targets, cases,and airjets may be used, if desired.

I claim as my inventionl. The combination, in an apparatus forpulverizing grain, ores, and other materials, of a supply-pipe, ajet-pipe from which air under a high pressure is caused to issue, atarget against which the material to be shattered is hurled, and a casesurrounding the target and suiciently close to the same to confine theair, and against which case the materials are hurled by the current ofair as they aredeilected from the target, substantially as set forth.

2. In an apparatus for pulverizing grain and other material, thecombination, with the supply-pi pe, the jet-pipe, and the target, of acase around the target, against which the material is hurled as it isdeflected from-the target, and which case is contracted, and a secondVpipe, and jet-pipe, connected with the case and a second target,substantially as specified, whereby the material receives two or moreshattering impacts in the apparatus, substantially as specified.

3. In an apparatus for pulverizing grain and other materials, thecombination, with the supply-tube and jet-tube for air under a highpressure, of aconvex target, against which the material is shattered andfrom which the said material passes freely as it rebounds, as set forth.

et. The combination, with the ejector and target in an apparatus forpulverizng grain and other materials, of a central support at the backof the target and a cross-bar for the same, substantially as set forth.

Signed by me this 15th day ot' April, A. D. 1880.

LEWIS SCUDDER CHICIIES'IER.

Witnesses WILLIAM G. Mo'r'r, CHAs. H. SMITH.

